1. Technical Field
The present invention relates to an improved LED tube structure capable of changing an illumination direction, which is for use in a lamp.
2. Description of Related Art
Nowadays, various lamps are used for illumination in the life space, and the lamps can be disposed at required positions of the space to change brightness of the space by means of light emitted therefrom, thereby to ensure good lighting conditions. Generally, tubular fluorescent lamps are most commonly used. The fluorescent lamp can emit bright light, but the frequency of the emitted light is less stable, which may have an adverse influence on eyesight health. Moreover, a problem of mercury pollution will occur when fluorescent lamps are manufactured and recycled.
As people's awareness of environmental protection is enhanced, conventional lamp bodies are gradually replaced with current LED tubes all over the world. The LED tubes completely obviate such problems related to environment pollution and hazards to human health and, moreover, save power substantially.
However, an LED lamp strip 10a of an LED tube 10 (as shown in FIG. 1) irradiates light from a single side (a conventional fluorescent lamp irradiates light within a 360-degree range), so light irradiation of the LED tube 10 is directional. The LED tube 10 is joined to a connecting receptacle 20 of a conventional fluorescent lamp holder in the way that terminals 101 at both sides of the LED tube 10 (as shown in FIG. 2) are firstly inserted into the connecting receptacle 20 at both sides of the fluorescent lamp to be preliminarily positioned, and then the LED tube 10 is rotated by an angle of about 90 degree so that the terminals 101 thereof are rotated to make contact with power contacts of the connecting receptacle 20 for positioning purpose. The conventional fluorescent lamp holder is generally disposed on a roof (as shown in FIG. 3), and the LED tube 10 can normally irradiate light downwards for illumination. However, if the conventional fluorescent lamp holder (as shown in FIG. 4) is fixed on a side wall, then the LED tube 10 will irradiate light in a lateral direction and cannot irradiate light downwards in a normal way.
In view of the problem of the irradiation direction of the LED lamp strip 10a of the LED tube 10 described above, the inventor has continuously tried to have the LED tube 10 change the illumination direction according to practical requirements and, through many researches and tests, eventually obtains an improved LED tube structure design.